Aylward SC, Reem RE. Pediatric Intracranial Hypertension. Pediatr Neurol. 2017 Jan;66:32-43.
Primary (idiopathic) intracranial hypertension has been considered to be a rare entity, but with no precise estimates of the pediatric incidence in the United States. There have been attempts to revise the criteria over the years and adapt the adult criteria for use in pediatrics. The clinical presentation varies with age, and symptoms tending to be less obvious in younger individuals. In the prepubertal population, incidentally discovered optic disc edema is relatively common. By far the most consistent symptom is headache; other symptoms include nausea, vomiting tinnitus, and diplopia. Treatment mainstays include weight loss when appropriate and acetazolamide. Furosemide may exhibit a synergistic benefit when used in conjunction with acetazolamide. Surgical interventions are required relatively infrequently, but include optic nerve sheath fenestration and cerebrospinal fluid shunting. Pain and permanent vision loss are the two major complications of this disorder and these manifestations justify aggressive treatment. Once intracranial hypertension has resolved, up to two thirds of patients develop a new or chronic headache type that is different from their initial presenting headache.
Until very recently, there have been no concrete estimates of pediatric intracranial hypertension in the United States. Unless physicians are paying attention to the literature, they may not even be using the current nomenclature for the condition, and use the older term “pseudotumor cerebri” instead.
Shawn Aylward MD, member of the Division of Neurology at Nationwide Children’s Hospital and director of the hospital’s Intracranial Hypertension Clinic, has sought to both spotlight and more clearly define the condition in a series of publications in the last year. While pediatric intracranial hypertension may be rare, his clinic saw 173 unique patients in 2016, and he is well aware that physicians can miss it.
“When it is not frequently encountered, it is often forgotten,” says Dr. Aylward, who is also an assistant professor of Clinical Pediatrics at The Ohio State University College of Medicine. “The stereotypical intracranial hypertension patient is postpubertal and overweight. Many clinicians would consider the condition if that patient presented with headaches or vision problems. But a slender, young child with headaches? Or an asymptomatic child who is discovered to have optic disc edema during a routine ophthalmic exam? Some clinicians may not think about it.”
Dr. Aylward was lead author of a recent invited review in Pediatric Neurology detailing the incidence, evaluation, diagnosis and treatment of pediatric intracranial hypertension – along with calling for the use of the terms “primary intracranial hypertension” and “secondary intracranial hypertension” (when a clear cause of increased cranial pressure can be found). “Pseudotumor cerebri” and “idiopathic intracranial hypertension” remain in wide use but can lead to confusion, says Dr. Aylward.
He was also the lead author of a 2016 publication in Pediatric Neurology examining the presentations of intracranial hypertension in a large pediatric cohort drawn from the Intracranial Hypertension Registry at the Intracranial Hypertension Research Foundation. While likely a population with more severe manifestations of the disease, the publication confirmed much of what researchers had found in smaller studies:
Headache was a reported symptom in 96.5 percent of patients with primary intracranial hypertension and 98.4 percent of those with secondary intracranial hypertension
Bilateral optic nerve edema was found in 89.3 percent and 78.7 percent, respectively
Most practitioners consider postpubertal obese females to be the classic intracranial hypertension patient, but only 21.2% of patients fit this description
Prepubertal primary intracranial hypertension patients had a female-to-male ratio of 1:1.04 (lower than that found in the literature) but postpubertal patients had a ratio of 6:1 (higher than ratios reported elsewhere)
Because of various findings about the prevalence of optic nerve edema, a fundoscopic exam is essential in an initial evaluation for intracranial hypertension.
“If clinicians are not comfortable with fundoscopy, they should refer the patients to an ophthalmologist, ” says Dr. Aylward. “Our clinic is a joint venture between Neurology and Ophthalmology at Nationwide Children’s, and it is common that a patient comes to us over concerns for edema found by an outside practitioner. It’s important that after such a finding, we see a patient relatively quickly.”
Defining and treating pediatric intracranial hypertension is important, and it’s been an obvious focus of the clinic at Nationwide Children’s. With so many patients being followed, Dr. Aylward and his colleagues believe they can now begin moving toward researching potential causes.
“We have this all this data, from children who have been evaluated, diagnosed and treated here,” he says. “We are now trying to figure out why they have this condition at all.”